Experiment study on etching process of graphite electrode by DC hydrogen plasma

Abstract

DC (direct current) graphite electrodes were used to investigate the hydrogen plasma etching characteristics. Results show that the intermittent spark is marked by physical etching, whereas glow discharge is marked by chemical etching. CH4 is the main gas product, together with the existence of C2H6, C2H4, C3H8, and C3H6. A detailed analysis of the 20‐mA glow discharge showed that the chemical reactions due to the plasma occur mainly through hydrogenation reactions on graphite defects, and different plasma action zones on the graphite also play different roles. Additionally, plasma gaseous reaction processes were analyzed through free radical reactions.